Vibbation-absobbing offiounting



P. W. BRIDGMAN'. VIBRATION ABSORBING MOUNTING.

APPLICATION FILE-D SEPT. 6. 191-9..

- Patented May '10, 1921.

3 SHEETS-SHEET I.

INVENTOR. P. P- B P. W. BRIDGMAN.

VIBRATION ABSOHBING MOUNTING APPLICATION FIE-ED SEPT- 6, 1919' PM IBMPatented May 192 a SHEETS-SHEET '2.

P. W. BRI'DGMAN.

VIBHAHON ABSORBING MOUNTING.

APPLICATION FILED sEPT.6. 1919,

1,377,556, 7 Patented May 10, 1921.

3 SHEETS-SHEET 3.

- INVENTOR. 'PAv. 13W

I its 1 UNITED J'T TEIsI OFFICE.

- rnncy BRIDGMAN, or 'cnMBnInGn, MASSACHUSETTS. I

. vmRA'rxoiwnBsonBING ivroun'rme.

To all whom it may) concern I f :i Be it known that.I',PERCY WV.BRIDGMAN,

a citizen of thefUnited States residing at Cambridge, in the. county oillliddlesexand State of Massachusetts; have invented new and usefulImprovements in" Vibration-Ab sorbing Mountings, of which the fell is aspecification. The present invention'relates to a vibration absorbingmountingfand particularly 1 to a vibration absorbing mount ng formachinery or the llke to prevent the vibration I ofthe machinery frombeing transmitted to support. mountingmay also be jusedto prevent vibrations from being transmitted to the apparatus mounted thereon." Although"applicable to vibrations of all frequencies, itfis ing isofparticular'applicationto the mounting of eng1nes, pumps', dynamos, andthe like, on sh pboard so as to prevent the v brations from beingcommunicated to the ships frameand therebyto the water, making possiblea more, quiet ship and one more difiicult to detect by submarinelistening devicesf lteferringto theidrawin'gs, Figure l. is aperspective view of aplatfor n provided with the vibration absorbingmounting.

.Fig. 2 is apersp'ectiye iew of one ofthe mountlngpads, Fig. 3 man endelevatlon of the mounting pad. Fig. 4 is side elevation ofthe mountingpad. Fig.5 is 'a section along the line V-V of- Fig. 4. Fig. 6 is a sideelevation of a modification. Fig. 7 is a perspective view of themodificationshown f .placed in a vertical position, one of the of theinvention, reference numeralll gindi cates the platform upon whichmachine orj other apparatus is to be mounted.

T This platform is supportedbythe vibration absorbingmountingsindic'ated in Fig., 1as

four mountings I {or corners of the plate.

' Referring particularly to Figs. 2 and 5, the vibration absorbingmountingcomprises pads}, placed under the a supporting member orplate 2and asup ported member-or plate 3. The plate 2 has a plurality ofupright ribs 4-. The plate. 3 has a plurality of downwardly extend ngribs 5, which are alternatelyspaced with The vibration absorbing Specifi cationof Letters Patent. Patented May 10, 1921. Application filed S'rimter 6, 1919. Serial no. 322,272. I F i Z respectfto the ribs 4. Whileit 'is usually and tli'eother members have a single rib bearing on thesprings, between the ribs of first member.v The ribs 4 and 5 formbearing po nts or members acting against the bars 7, at the outside ribstqlWhen weight is put upon supported plate 3, the springs Gare displacedlaterallyin respect to their f faxes, in a downward direction, at thepoints oi 'contact with the ribs 5'. f This 'causes the springs, toassume the undulating form shown in Fig. 1." The downward thrust of theribs 5'is resisted bvthe upward com poi'ients ofthe tension of thespring. The resistance of the springs is primarily due to theirlengthwise tension and not to their lateral stiffness, aslthe helicalsteel springs springs 6 which arestretched across them. ZThe springs 6are preferablyflexible, strong, steel helical springs. Thesprings arepref- 1 Lerably put under some initial tension, and the ends'of thespringsfare held by cross are flexible and have but little lateral Istiflfness. f' In the form of the, invention shown in Figs. 2 and 5, theribs at4, and 5, have holes through which are passed the springs 6.

This obviates any danger of the .mounting coming apart and adaptsit foruse'as a supporting mounting 'of the suspension type. i F orexampl'e,the upper plate 3 may be fixed to an, overhead support and the kapparatus to be mounted may be hung from the plate -2. Themounting mayalso be plates being fastened to a wall.

As shown in Fig. 1, four mountingsare I placed under the [corners of thesupport platform 1. The mountingpad 10,has its ribs extended at rightangles to the adjacent'mounting'pad ll. Thisjis for the purpose ofpreventing" the ribs from sliding longitudinally along' the springs. Anytendencyof the downwardly extended ribs 5 70f the mounting 10 to slidealongthe springs will. be resisted by the mounting 11,'in which "theribs run in the opposite direction. I i

Figs- 6 and? illustrate a modificationin which the springs 16, arestretched over the tops of the ribs 14, infiead of passing through holestherein. The ribs 15, of the supported member, bear against the springs16, at points intermediate to ribs 14. The sidewise displacement orseparation of the supported and supportingplates 12 and 13, is preventedby corner guides 20, which form a loose fit around the corners of theupper plate 13, permitting it to move downward when weight is placedupon it.

The springs effectively prevent the transmission of vibrations from thesupported to the supporting plate or vice versa. The ribs t and 5, canvibrate relatively to each other in a direction longitudinal to the axesof the springs 6, the vibration being'absorbed by the small lengtheningand shortening of the spring lengths between the ribs. The ribs 4 and 5are also free to vibrate relatively to each other in a plane at rightangles to the axis ofthe springs 6. Vibrations in thisplane, whetherverti.

cal or horizontal, cause small displacements of the points of bearing ofthe ribs on the springs in a direction at right angles to the axis ofthe springs, the springs lengthening and shortening to permit this. i Itwill be seen that no component of the relative vibration between thesupported and supporting plate is resisted by a rigid connection betweenthem, but every component is resisted by a yielding spring tension whichefiectively prevents the transmission of the vibrations. The mountingsmaybe made up in units as shown in Figs. 2 to 5 and applied as neededbeneath the apparatus to be supported as shown in Fig. 1. If greaterweight is to be carried the springs may be made heavier or their numbermay be increased. If a light weight is to be carried, rubber bands maybe advantageously employed in place of the helical springs. The

form shown in F igs, 6 and 7 is particularly adapted to use with rubberbands. The term flexible tension spring, as used in the claims, isintended as a term of description and not of: limitation and toincludesuch forms of spring-like members as rubber bands or the like,which have the property of being flexible to transverse bending, butwhich exert anendwise ten sion. H

The present invention is not limited to its illustrated embodiment butmay be embodied in other structures within the scope of the followingclaims:

V Iclaim: v

- 1. A vibration absorbing mounting comprising supporting and supportedmembers extended across the ribs parallel to the plates and formingyielding connections between them, substantially as described{ 4. A.vibration absorbing mounting comprising supporting and supported plateshaving alternately disposed opposing ribs anda plurality of helicalsprings stretched across the ribs parallel to the plates and formingyielding connections between the two sets of ribs, substantially asdescribed. 5. A vibration absorbing mounting com prising supporting andsupported plates provided with alternately disposed oppo sitelyextending ribs, having alinedholes therethrough and a plurality oftension springs extending across theribs, through the holes, parallel tothe plates, and forming yielding connections between the two sets ofribs, substantially as described.

6. A vibration absorbing mounting comprising opposed supporting andsupported members andthree equal ribs, one of said members having two ofthe ribs and a plurality of flexible tension springs extending betweenthem, the other of said members having the third rib laterallycompressing the tension springs at points between the first mentionedribs, substantially as described.

7. A vibration absorbing mounting comprising supporting and supportedmembers, one of said members having two spaced bearing points and aflexible tensionvmember extending between them, and the other of saidmembers having a bearing point engaging the tension member at .a pointbetween the two first mentioned bearing points and by its thrustdisplacing the tension member at that point, the thrust being yieldinglyresisted by the opposing component of the longitudinal tension of thetension member, substantially as described.

